M150 Strange Ignition Timing Issue
Posted: Mon May 08, 2017 12:30 pmHello all, I am from the University of Missouri FSAE team. This is our first year using MoTeC, and we are running an M150 with a CBR600RR engine in our FSAE car. The engine starts up and runs perfectly most of the time, making power and responding as we expect it to. Sometimes however, usually when restarting after a hard driving session, our car gets 'stuck' with very little power. When trying to drive like this our exhaust gets extremely hot (glowing red) and we usually have to stop driving for the day. I realize this could be some other mechanical issues but wanted see if anyone has any ideas on the electrical side of things.
I think what might be happening is that the timing somehow ends up 10-20 degrees retarded and we are burning a lot of fuel when the engine does this. It is a very binary thing, the engine either runs perfectly or it won't rev past much past 12000 and the headers start glowing. I have been able to reproduce this issue on the track and on the dyno consistently, always when restarting after running the engine hard. Sometimes I try to let it idle for 3-5 minutes before driving again and it usually doesn't cause this problem.
I tried checking the timing with a timing light and it always behaves very strangely. With my Crank Reference Offset set to 461 degrees (what you reccomend for our engine). I have the ECU set to "check timing" at 15 degrees for idle and the timing light tells me I am at around 50 degrees. When revving the engine up near about 6000 rpm this number climbs linearly to near 80-90 degrees (even with the ECU locked to 15 degrees). I don't think it's possible that this is right because the engine should start knocking a lot sooner and wouldn't run at all. I've tried with another timing light and got the same results, so I don't think the light is the issue.
I don't think our engine is actually running at these numbers, because with the tune I have on it currently the engine performs perfectly (except for when the glowing exhaust issue happens). I have read before that VR sensors like the ones in our CBR motor can drift like this with rpm, but it doesn't look like the GPR package has any sort of compensation for this. Other this, I have no idea what causes our engine to run poorly sometimes, or why testing with a timing light gives weird results. Again, the engine issue is a very on or off thing.
I realize its hard to debug things like this without seeing our setup, but if anyone has any ideas as to whats wrong or any other tests I would appreciate it. I have also attached the M1 configuration we are using.
I think what might be happening is that the timing somehow ends up 10-20 degrees retarded and we are burning a lot of fuel when the engine does this. It is a very binary thing, the engine either runs perfectly or it won't rev past much past 12000 and the headers start glowing. I have been able to reproduce this issue on the track and on the dyno consistently, always when restarting after running the engine hard. Sometimes I try to let it idle for 3-5 minutes before driving again and it usually doesn't cause this problem.
I tried checking the timing with a timing light and it always behaves very strangely. With my Crank Reference Offset set to 461 degrees (what you reccomend for our engine). I have the ECU set to "check timing" at 15 degrees for idle and the timing light tells me I am at around 50 degrees. When revving the engine up near about 6000 rpm this number climbs linearly to near 80-90 degrees (even with the ECU locked to 15 degrees). I don't think it's possible that this is right because the engine should start knocking a lot sooner and wouldn't run at all. I've tried with another timing light and got the same results, so I don't think the light is the issue.
I don't think our engine is actually running at these numbers, because with the tune I have on it currently the engine performs perfectly (except for when the glowing exhaust issue happens). I have read before that VR sensors like the ones in our CBR motor can drift like this with rpm, but it doesn't look like the GPR package has any sort of compensation for this. Other this, I have no idea what causes our engine to run poorly sometimes, or why testing with a timing light gives weird results. Again, the engine issue is a very on or off thing.
I realize its hard to debug things like this without seeing our setup, but if anyone has any ideas as to whats wrong or any other tests I would appreciate it. I have also attached the M1 configuration we are using.